(04/13/26) CLINTON, La. — With Louisiana’s quail hunting season lasting from late November to the end of February, we’re still the better part of a year away from this year’s start. But LSU AgCenter researchers are studying declining populations by testing for a disease first discovered in another bird associated with late November: turkeys.

At the AgCenter’s Bob R. Jones-Idlewild Research Station in Clinton, AgCenter veterinarian Dr. Jim LaCour has been studying the bird protozoan blood parasite leucocytozoon, an organism transmitted by black flies (Simuliidae). Black flies were first documented in Louisiana circa 2010 by his mentor, former AgCenter entomologist Lane Foil, who died last year. Leucocytozoon infection in birds can cause anemia, organ dysfunction, reproductive disorders, emaciation and eventually death.

Foil hypothesized there was a correlation between the invasive black fly, a carrier of the parasite, and wild turkey population decline at the time, especially in the Florida Parishes. It was hypothesized that leucocytozoon was at least partially responsible for the falloff.

LaCour, who previously was the Louisiana Department and Wildlife and Fisheries’ state wildlife veterinarian, has been carrying on Foil’s research.

Last year, LaCour and his researchers placed domestic turkeys outdoors in predator-proof cages to expose them to flying insects. Blood was collected at two-week intervals to test for the disease, leading to all 19 turkeys in the study testing positive for leucocytozoon.

LaCour said the parasite didn’t seem to cause mortality in other types of birds that were studied around the same time. But, he added, turkeys can contract other immunosuppressive retroviral diseases that, when combined with leucocytozoon, can cause death.

Because quail populations have been declining in Louisiana for a longer period than wild turkeys, Foil and LaCour wondered if quail could be infected by the parasite, potentially leading to their population decline as well.

“We were injecting the birds with leucocytozoon-infected blood, keeping them separated where they won’t be exposed outside to see if we can transmit it by blood,” he said. “We are also putting quail out in cages near the woods, so they will be exposed to the black flies.”

An entomology postdoctoral researcher of Foil’s, Dinesh Erram, has been conducting polymerase chain reaction tests, a chemical test for the organism in quail. The same tests in turkeys detected the blood parasites two weeks before they could be detected microscopically.

LaCour acknowledged that other factors could have led to the quail decline, such as herbicide usage and changes in farming practices that reduced the thickets along fence rows where quail live.

“Quail habitats change. For example, we know that we have more fire ants now than we had in the 1960s and 1970s, and they have been shown many times to get on ground-nesting birds’ eggs when they hatch,” LaCour said. “They aren’t typically in the woods, where turkeys may nest, but they’re in fields, where quail do.”

On the bright side, LaCour said there was no indication while studying the eggs that the disease can be transmitted to embryos in turkeys.

Associate director of the Louisiana Agriculture Experiment Station and Idlewild coordinator Glen T. Gentry said the research being conducted is the first step in providing answers for the public.

“Once we understand what’s happening with these birds, the next step will be turning that science into management practices,” said Gentry. “That means outlining actions landowners can take, priorities for agencies and ways partners can help to turn these populations around.”

LaCour said black flies are just beginning to come out now, with peak transmission in mid-April in turkeys. He assumes quail would have the same transmission times.

He expects study results to be complete in June or July.

“Our hypothesis is there will be some transmission, and if we do see that, then the next question is are the birds ill? If so, is it because of the blood parasite?” he said. “We’ll be seeing them every day, so we can analyze them, see if they’re not eating or losing weight or doing any of those things that sick animals do. If there isn’t a problem, it’s just a good scientific finding. If there is a problem, we start thinking about what we can do to solve it.”

LSU AgCenter veterinarian Dr. Jim LaCour examines quail kept in predator-proof cages to expose them to flying insects at the Bob R. Jones-Idlewild Research Station in Clinton. LaCour is conducting research to determine if quail are susceptible to Leucocytozoon, a blood parasite carried by black flies that has caused illness in wild turkeys. LaCour named the quail cage after his mentor, former AgCenter entomologist Lane Foil, who died last year. Photo by V. Todd Miller/LSU AgCenter

Indoor pens at the LSU AgCenter Bob R. Jones-Idlewild Research Station in Clinton keep black flies from reaching quail being held for research on Leucocytozoon, a blood parasite that has been found in wild turkeys. Photo by V. Todd Miller/LSU AgCenter

Quail in cages kept near the woods at the Bob R. Jones-Idlewild Research Station in Clinton are naturally exposed to black flies, which carry Leucocytozoon, a blood parasite that has caused illness in wild turkeys. Photo by V. Todd Miller/LSU AgCenter